Abstract : Newly hatched and eight day-old chicks induced maternal responses in hens without previous maternal experience. However, maternal behaviour emerged sooner in hens confined with younger chicks. Replacement of eight or 15 day-old chicks by newly-hatched ones, clearly indicated that all hens, whatever their prior experience, were capable of immediately expressing appropriate maternal responses, including high brooding amount. Brooding stances were mainly exhibited towards very young chicks (i.e. one or two days old).
